26 Chapter I. 



debouching into the Arctic Sea, to supply this water. 

 The fluvial basin of these rivers is very considerable, 

 comprising a large portion of Northern Europe, almost 

 the whole of Northern Asia or Siberia down to the Altai 

 Mountains and Lake Baikal, together with the principal 

 part of Alaska and British North America. All these 

 added together form no unimportant portion of the 

 earth, and the rainfall of these countries is enormous. 

 It is not conceivable that the Arctic Sea cf itself could 

 contribute anything of importance to this rainfall ; for, in 

 the first place, it is for the most part covered with drift- 

 ice, from which the evaporation is but trifling ; and, in 

 the next place, the comparatively low temperature in 

 these regions prevents any considerable evaporation 

 taking place even from open surfaces of water. The 

 moisture that produces this rainfall must consequently in 

 a great measure come from elsewhere, principally from 

 the Atlantic and Pacific Oceans, and the amount of water 

 which thereby feeds the Arctic Sea, must be very con- 

 siderable. If we possessed sufficient knowledge of the 

 rainfall in the different localities it might be exactly 

 calculated.* 



" The importance of this augmentation appears even 



' Since writing the above I have tried to make such a calculation, 

 and have come to the conclusion that the aggregate rainfall is not so 

 large as I had at first supposed. See my paper in The Norwegian 

 Geographical Society's Annual, III, 1891-92, p. 95 ; and The Geo- 

 graphical Journal ', London, 1893, p. 5. 



